Re: Removing Control Characters from a File

This will remove ^X's from your file

perl -0777lpwi -030e0  your_file
[download]

Study of man perlrun will explain why this works.

Abigail

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Re: Re: Removing Control Characters from a File by jmcnamara (Monsignor) on Jun 04, 2002 at 22:57 UTC
Very nice. This merits a closer look: `perl -0777lpwi -030e0 file 0777 Set $/ to 0777. l Chomp $\ and set $\ = $/. Thus $\ = 0777. p Loop over file and print. w Turn warnings on. i Make the changes in-place. 030 Set $/ to 030 (^X). $\ is still 0777. e0 Empty program.` [download] So in effect this splits the file into records divided by `^X`, chomps `^X` from the end of each record and prints out the records with `0777` appended at the end. However, (and I'm not certain about this) since there is no character with that value it actually appends `''`. Thus, the `^X`'s are removed from the file. So in a way the program is functionally equivalent to: `perl -i -pe 's/\30//g' file` I say functionally equivalent since there is no aesthetic equivalence. `:-)` -- John.	[reply] [d/l] [select]

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Re: Re: Removing Control Characters from a File
by jmcnamara (Monsignor) on Jun 04, 2002 at 22:57 UTC

    perl -0777lpwi -030e0 file

    0777    Set $/ to 0777.
    l       Chomp $\ and set $\ = $/. Thus $\ = 0777.
    p       Loop over file and print.
    w       Turn warnings on.
    i       Make the changes in-place.
    030     Set $/ to 030 (^X). $\ is still 0777.
    e0      Empty program.
[download]

So in effect this splits the file into records divided by ^X, chomps ^X from the end of each record and prints out the records with 0777 appended at the end. However, (and I'm not certain about this) since there is no character with that value it actually appends ''. Thus, the ^X's are removed from the file.

So in a way the program is functionally equivalent to: perl -i -pe 's/\30//g' file

I say functionally equivalent since there is no aesthetic equivalence. :-)

--
John.

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